The object was thrown horizontally, so the initial velocity is irrelevant. From Newton's Second
$\begin{align*}h = \frac{1}{2} \cdot 9.8 \mbox{ m/s/s} \cdot \left(2.0 \mbox{ s}\right)^2 = \boxed{19.6 \mbox{ m}}\end{align*}$
Therefore, answer (D) is correct.

Solution to 2008 Problem 2